title: Foodborne nosocomial outbreak of SHV1 and CTX-M-15-producing Klebsiella pneumoniae: epidemiology and control.
abstract: BACKGROUND
  We describe a foodborne nosocomial outbreak due to extended-spectrum β-lactamase (ESBL)-producing Klebsiella pneumoniae.
  
  
  METHODS
  An outbreak of ESBL K. pneumoniae was detected in March 2008. Initial control measures included contact isolation and a protocol for routine detection and reinforcement in hand hygiene practices. ESBL producers were screened for the bla(TEM), bla(SHV), and bla(CTX-M) genes. Pulsed-field gel electrophoresis analysis was performed using XbaI as a restriction endonuclease.
  
  
  RESULTS
  One hundred fifty-six colonized and/or infected patients were identified, 35 (22.4%) of whom had infection. The outbreak affected all hospital wards. Fecal carriage was up to 38% of patients in some wards. Of note, investigation revealed a very short delay between admission and colonization. None of the health care workers or environmental surfaces in the wards was found to be colonized. This prompted an epidemiological investigation of a possible foodborne transmission. We found that up to 35% of the hospital kitchen-screened surfaces or foodstuff were colonized and that 6 (14%) of 44 food handlers were found to be fecal carriers. Phenotypic and genotypic analysis of all clinical, environmental, and fecal carrier isolates showed the dissemination of a single strain of SHV-1 and CTX-M-15-producing K. pneumoniae. At that time, structural and functional reforms in the kitchen were performed. These were followed by a progressive reduction in colonization and infection rates among inpatients until complete control was obtained in December 2008. No restrictions in the use of antibiotics were needed.
  
  
  CONCLUSIONS
  To our knowledge, this is the first reported hospital outbreak that provides evidence that food can be a transmission vector for ESBL K. pneumoniae.
authors.affiliation: Infectious Diseases Unit, Service of Internal Medicine, Hospital Universitari Mútua de Terrassa, Barcelona, Spain. esthercalbo@hotmail.com
authors.forename: Esther
authors.initials: E
authors.lastname: Calbo
authors.forename: Núria
authors.initials: N
authors.lastname: Freixas
authors.forename: Mariona
authors.initials: M
authors.lastname: Xercavins
authors.forename: Montserrat
authors.initials: M
authors.lastname: Riera
authors.forename: Carmen
authors.initials: C
authors.lastname: Nicolás
authors.forename: Olga
authors.initials: O
authors.lastname: Monistrol
authors.forename: Maria Del Mar
authors.initials: Mdel M
authors.lastname: Solé
authors.forename: M Rosa
authors.initials: MR
authors.lastname: Sala
authors.forename: Jordi
authors.initials: J
authors.lastname: Vila
authors.forename: Javier
authors.initials: J
authors.lastname: Garau
mesh_terms: D000368:Aged; D015373:Bacterial Typing Techniques; D016000:Cluster Analysis; D003428:Cross Infection / Q000453:epidemiology* / Q000382:microbiology; D015252:Deoxyribonucleases, Type II Site-Specific / Q000378:metabolism; D004196:Disease Outbreaks; D016521:Electrophoresis, Gel, Pulsed-Field; D005260:Female; D005517:Foodborne Diseases / Q000453:epidemiology* / Q000382:microbiology; D005838:Genotype; D006801:Humans; D007710:Klebsiella Infections / Q000453:epidemiology* / Q000382:microbiology; D007711:Klebsiella pneumoniae / Q000145:classification / Q000201:enzymology* / Q000235:genetics / Q000302:isolation & purification; D008297:Male; D058889:Molecular Typing; D001618:beta-Lactamases / Q000096:biosynthesis* / Q000235:genetics
chemical_list: C025580:endodeoxyribonuclease XBAI; D015252:Deoxyribonucleases, Type II Site-Specific; D001618:beta-Lactamases